ui/vnc: fix vmware VGA incompatiblities

this fixes invalid rectangle updates observed after commit 12b316d
with the vmware VGA driver. The issues occured because the server
and client surface update seems to be out of sync at some points
and the max width of the surface is not dividable by
VNC_DIRTY_BITS_PER_PIXEL (16).

Reported-by: Serge Hallyn <serge.hallyn@ubuntu.com>
Signed-off-by: Peter Lieven <pl@kamp.de>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

1 files changed, 7 insertions, 3 deletions

diff --git a/ui/vnc.c b/ui/vnc.c
index 9c84b3e0fd..5925774509 100644
--- a/ui/vnc.c
+++ b/ui/vnc.c
@@ -888,7 +888,7 @@ static int vnc_update_client(VncState *vs, int has_dirty, bool sync)
         VncDisplay *vd = vs->vd;
         VncJob *job;
         int y;
-        int height;
+        int height, width;
         int n = 0;
 
         if (vs->output.offset && !vs->audio_cap && !vs->force_update)
@@ -907,6 +907,7 @@ static int vnc_update_client(VncState *vs, int has_dirty, bool sync)
         job = vnc_job_new(vs);
 
         height = MIN(pixman_image_get_height(vd->server), vs->client_height);
+        width = MIN(pixman_image_get_width(vd->server), vs->client_width);
 
         y = 0;
         for (;;) {
@@ -925,8 +926,11 @@ static int vnc_update_client(VncState *vs, int has_dirty, bool sync)
                                     VNC_DIRTY_BPL(vs), x);
             bitmap_clear(vs->dirty[y], x, x2 - x);
             h = find_and_clear_dirty_height(vs, y, x, x2, height);
-            n += vnc_job_add_rect(job, x * VNC_DIRTY_PIXELS_PER_BIT, y,
-                                  (x2 - x) * VNC_DIRTY_PIXELS_PER_BIT, h);
+            x2 = MIN(x2, width / VNC_DIRTY_PIXELS_PER_BIT);
+            if (x2 > x) {
+                n += vnc_job_add_rect(job, x * VNC_DIRTY_PIXELS_PER_BIT, y,
+                                      (x2 - x) * VNC_DIRTY_PIXELS_PER_BIT, h);
+            }
         }
 
         vnc_job_push(job);